the character of our country once more. >> reporter: tonight, dzhokhar tsarnaev is in serious condition at beth israel medical center, being treated for his injuries. and the city can finally sleep. for "nightline," i'm linsey davis in watertown, massachusetts. >> our thanks to linsey davis. >>> coming up next for us, faces of terror. what drove these proverbial boys next door to unlaunch allegedly a deadly reign of terror. progressive direct and other car insurance companies? yes. but you're progressive, and they're them. yes. but they're here. yes. are you...? there? yes. no. are you them? i'm me. but those rates are for... them. so them are here. yes! you want to run through it again? no, i'm good. you got it? yes. rates for us and them -- now that's progressive. call or click today. cheryl burke is cha-cha-ing in depend silhouette briefs for charity, to prove that with soft fabric and waistband, the best protection looks, fits, and feels just like underwear. get a free sample and try for yourself. >>> this special edition of "nightline," caught, continues from boston with juju chang.